Siblings Fernando: Prince Luís of Portugal, Princess Maria of Aragon, Marchioness of Tortosa; Prince Alfonso of Portugal, Princess Beatriz of Castille, Countess of Alburquerque and Haro; Prince João of Portugal, Lord of Porto de Mós, Ceia and Montelonso, and also Duke of Valencia de Campos; Prince Dinis of Portugal, Lord of Villar-Dompardo, Cifuentes, Escalona and Alvar de Tormes and King João I of Portugal

Ferdinand I (Portuguese: Fernando, pronounced[fɨɾˈnɐ̃du]; Lisbon, 31 October 1345 – 22 October 1383 in Lisbon), sometimes referred to as the Handsome (Portuguese: o Formoso) or rarely as the Inconstant (Portuguese: o Inconstante), was the ninth King of Portugal and the Algarve, the second but eldest surviving son of Peter I and his wife, Constance of Castile. He succeeded his father in 1367.On the death of Pedro of Castile in 1369, Ferdinand, as great grandson of Sancho IV by the female line, laid claim to the vacant throne, for which the kings of Aragon and Navarre, and afterwards John of Gaunt, duke of Lancaster (married in 1370 to Constance, the eldest daughter of Pedro), also became competitors.Meanwhile Henry of Trastamara, the brother (illegitimate) and conqueror of Pedro, had assumed the crown and taken the field. After one or two indecisive campaigns, all parties were ready to accept the mediation of Pope Gregory XI. The conditions of the treaty, ratified in 1371, included a marriage between Ferdinand and Leonora of Castile. But before the union could take place the former had become passionately attached to Leonor Telles de Menezes, the wife of one of his own courtiers, and having procured a dissolution of her previous marriage, he lost no time in making her his queen.This strange conduct, although it raised a serious insurrection in Portugal, did not at once result in a war with Henry; but the outward concord was soon disturbed by the intrigues of the duke of Lancaster, who prevailed on Ferdinand to enter into a secret treaty for the expulsion of Henry from his throne. The war which followed was unsuccessful; and peace was again made in 1373. On the death of Henry in 1379, the duke of Lancaster once more put forward his claims, and again found an ally in Portugal; but, according to the Continental annalists, the English proved as offensive to their companions in arms as to their enemies in the field; and Ferdinand made a peace for himself at Badajoz in 1382, its being stipulated that Beatrice, the heiress of Ferdinand, should marry King John I of Castile, and thus secure the ultimate union of the crowns.

Dona Leonor (Elionor) Telles (Teles) de Menezes (Meneses) (1350 - April 27, 1386), called by the people at her time a Aleivosa ("The Treacherous"), was queen consort of Portugal during the 14th century. Born in Trás-os-Montes e Alto Douro, she served as queen consort from 1372 to 1383 and as regent from 1383 to 1384.Married at a young age to a courtier named Dom João Lourenço da Cunha, 3rd Senhor de Pombeiro, with whom she had a son, Dom Álvaro da Cunha, she would be seduced by Ferdinand I of Portugal when he was a prince. This would occur while Leonor was visiting her sister Maria Telles, lady-in-waiting to Ferdinand's half-sister Beatrice, infanta of Portugal.Ferdinand managed to annul her first marriage to João Lourenço da Cunha on grounds of consanguinity and on May 5, 1372 secretly married Leonor Telles de Menezes.

Married at a young age to a courtier named Dom João Lourenço da Cunha, 3rd Senhor de Pombeiro, with whom she had a son, Dom Álvaro da Cunha, she would be seduced by Ferdinand I of Portugal when he was a prince. This would occur while Leonor was visiting her sister Maria Telles, lady-in-waiting to Ferdinand's half-sister Beatrice, infanta of Portugal.Ferdinand managed to annul her first marriage to João Lourenço da Cunha on grounds of consanguinity and on May 5, 1372 secretly married Leonor Telles de Menezes.

Well, several books say that she seduced him but the effects are the same.

Leonor was accepted as Queen by all nobles of the kingdom except by D. Diniz, the son of Inês de Castro... Funny how he didn't accept Leonor when his own mother was a lover of King Pedro I when he was still married with Dª Constança, Princess of Castela.

Leonor and Andeiro were lovers when King Fernando was still alive. This fact had a strong impact on Fernando's health.

Well, several books say that she seduced him but the effects are the same.

Leonor was accepted as Queen by all nobles of the kingdom except by D. Diniz, the son of Inês de Castro... Funny how he didn't accept Leonor when his own mother was a lover of King Pedro I when he was still married with Dª Constança, Princess of Castela.

Leonor and Andeiro were lovers when King Fernando was still alive. This fact had a strong impact on Fernando's health.

So, why is she referred to as "The Treacherous"? Reading her history, and given that these other references indicate that it was she who seduced Ferdinand I, it does seem that she was finding herself (perhaps through her own efforts) in positions of increasing power and status. Would it be safe to assume that perhaps she manipulated people and circumstances to increase her position and hence, that is how she became known as "The Treacherous"? In any event, that label does imply she was someone you didn't want to be close to.

So, why is she referred to as "The Treacherous"? Reading her history, and given that these other references indicate that it was she who seduced Ferdinand I, it does seem that she was finding herself (perhaps through her own efforts) in positions of increasing power and status. Would it be safe to assume that perhaps she manipulated people and circumstances to increase her position and hence, that is how she became known as "The Treacherous"? In any event, that label does imply she was someone you didn't want to be close to.

Leonor planned the death of her sister, Maria.

Maria Teles had (secretly) married D. João (the son of King Pedro and Inês). For some nobles, this son was the right heir to the throne.

Leonot felt her sister was taking power from her... So what Leonor did was to persuade the weak prince, telling him that if he were free to marry his niece Beatriz (the daughter of Leonor and Fernando), he would surely gain the crown.

It's sad but the weak and ambitious prince listened to her...

In Coimbra, the prince informed his friends that his wife was under suspicions of infidility... (a rumour that Leonor had spread). His next step would be to caught his wife in adultery and punish her with death.

He didn't caught her in adultery... but when he arrived to his Palace in Coimbra, the prince found her wife naked and the door of her room semi-open (left open by the servants...).

His friends found themselves unable to stop the prince who continue to hack at her until she was dead.

Leonor also arranged the deaths of two other children of Pedro and Inês.

Leonor didn't succeed. The next King of Portugal would be a bastard: D. João (Master of Aviz), the son of King Pedro and his mistress Teresa.
The Master of Aviz became the founder of a new Dynasty: the Dynasty of Aviz.

Maria Teles had (secretly) married D. João (the son of King Pedro and Inês). For some nobles, this son was the right heir to the throne.

Leonot felt her sister was taking power from her... So what Leonor did was to persuade the weak prince, telling him that if he were free to marry his niece Beatriz (the daughter of Leonor and Fernando), he would surely gain the crown.

It's sad but the weak and ambitious prince listened to her...

In Coimbra, the prince informed his friends that his wife was under suspicions of infidility... (a rumour that Leonor had spread). His next step would be to caught his wife in adultery and punish her with death.

He didn't caught her in adultery... but when he arrived to his Palace in Coimbra, the prince found her wife naked and the door of her room semi-open (left open by the servants...).

His friends found themselves unable to stop the prince who continue to hack at her until she was dead.

Leonor also arranged the deaths of two other children of Pedro and Inês.

Leonor didn't succeed. The next King of Portugal would be a bastard: D. João (Master of Aviz), the son of King Pedro and his mistress Teresa.
The Master of Aviz became the founder of a new Dynasty: the Dynasty of Aviz.

Wow! Leonor would make Lady Macbeth look like a saint. Well, like I said, she is certaintly someone you would not want to be close to. Thanks for the information.